Does anyone know what brand of stemware this is?
 

I recently received a pair of wine glasses with this etched on the bottom. Someone said it was Riedel, but the Riedels I've seen either say, "Riedel" or "JR". Anyone have any idea about this one?https://scontent-a-sea.xx.fbcdn.net/...99854124_n.jpg

I do not think I have seen that one, but here is a good place to start your research:

http://www.glassbottlemarks.com/bottlemarks-3/

Edited to add: Welcome to Flyertalk!

Can you tell us what's to the left of the "G". It looks like maybe an arrow, or is it another letter. I can't quite make it out from the picture. it isn't either Riedel or Schott.

The company is Glass Tech. It represents several stemware brands in the private logo/commercial market. Wineries and high-end event planners use them a lot. I think it may also be owned/partly owned by a German stemware manufacturer.

Your stemware may very well be Riedel but maybe a particular line made for commercial use. Many Glass Tech products are not marked with their actual brands but with the Glass Tech mark instead.